scholarly journals Simulations Reveal Adverse Hemodynamics in Patients With Multiple Systemic to Pulmonary Shunts

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Mahdi Esmaily-Moghadam ◽  
Bari Murtuza ◽  
Tain-Yen Hsia ◽  
Alison Marsden
Keyword(s):  
Blood Flow ◽  
Pulmonary Blood Flow ◽  
Thrombus Formation ◽  
Ductus Arteriosus ◽  
Pulmonary Atresia ◽  
Worst Case ◽  
Thrombotic Risk ◽  
Clinical Scenarios ◽  
Shunt Occlusion ◽  
Flow Competition

For newborns diagnosed with pulmonary atresia or severe pulmonary stenosis leading to insufficient pulmonary blood flow, cyanosis can be mitigated with placement of a modified Blalock–Taussig shunt (MBTS) between the innominate and pulmonary arteries. In some clinical scenarios, patients receive two systemic-to-pulmonary connections, either by leaving the patent ductus arteriosus (PDA) open or by adding an additional central shunt (CS) in conjunction with the MBTS. This practice has been motivated by the thinking that an additional source of pulmonary blood flow could beneficially increase pulmonary flow and provide the security of an alternate pathway in case of thrombosis. However, there have been clinical reports of premature shunt occlusion when more than one shunt is employed, leading to speculation that multiple shunts may in fact lead to unfavorable hemodynamics and increased mortality. In this study, we hypothesize that multiple shunts may lead to undesirable flow competition, resulting in increased residence time (RT) and elevated risk of thrombosis, as well as pulmonary overcirculation. Computational fluid dynamics-based multiscale simulations were performed to compare a range of shunt configurations and systematically quantify flow competition, pulmonary circulation, and other clinically relevant parameters. In total, 23 cases were evaluated by systematically changing the PDA/CS diameter, pulmonary vascular resistance (PVR), and MBTS position and compared by quantifying oxygen delivery (OD) to the systemic and coronary beds, wall shear stress (WSS), oscillatory shear index (OSI), WSS gradient (WSSG), and RT in the pulmonary artery (PA), and MBTS. Results showed that smaller PDA/CS diameters can lead to flow conditions consistent with increased thrombus formation due to flow competition in the PA, and larger PDA/CS diameters can lead to insufficient OD due to pulmonary hyperfusion. In the worst case scenario, it was found that multiple shunts can lead to a 160% increase in RT and a 10% decrease in OD. Based on the simulation results presented in this study, clinical outcomes for patients receiving multiple shunts should be critically investigated, as this practice appears to provide no benefit in terms of OD and may actually increase thrombotic risk.

Study of Multiple Systemic-to-Pulmonary Shunts in Single Ventricle Hearts

2012 ◽  
Author(s):  
Mahdi Esmaily Moghadam ◽  
Tain-Yen Hsia ◽  
Bari Murtuza ◽  
Alison Marsden
Keyword(s):  
Blood Flow ◽  
Pulmonary Blood Flow ◽  
Single Ventricle ◽  
Ductus Arteriosus ◽  
Adverse Outcomes ◽  
Flow Dynamics ◽  
Single Institution ◽  
Shunt Occlusion ◽  
Flow Competition ◽  
Blalock Taussig Shunt

For newborns diagnosed with single ventricle hearts and insufficient blood flow to the lungs, their lack of oxygen in the blood can be remedied with a modified Blalock-Taussig shunt (BTshunt) between the innominate and pulmonary artery. However, some surgeons prefer to have two systemic-to-pulmonary shunts, by either leaving the ductus arteriosus open or construct a second BT shunt, to provide additional pulmonary blood flow. There have been clinical reports of premature shunt occlusion when more than one shunt is employed, and a recent audit of shunt operations at a single institution has revealed increased mortality. There are speculation that these adverse outcomes can be due to flow competition between the two shunts, and/or having too much pulmonary blood flow. The flow dynamics and cardiopulmonary physiology in single ventricle circulations where pulmonary blood flow is supplied by more than one shunt has not been studied previously. In this study, we adopted CFD-based multi-domain simulations to compare a range of shunt configurations to examine the issue of flow competition and pulmonary overcirulation.

Tetralogy of Fallot With Pulmonary Atresia: Anatomy, Physiology, Imaging, and Perioperative Management

2020 ◽  
pp. 108925322092048
Author(s):  
Madhusudan Ganigara ◽  
Eyal Sagiv ◽  
Sujatha Buddhe ◽  
Aarti Bhat ◽  
Sathish M. Chikkabyrappa
Keyword(s):  
Blood Flow ◽  
Tetralogy Of Fallot ◽  
Pulmonary Blood Flow ◽  
Ductus Arteriosus ◽  
Pulmonary Arteries ◽  
Pulmonary Atresia ◽  
Sole Source ◽  
Aortic Insufficiency ◽  
Collateral Arteries ◽  
Antegrade Flow

Tetralogy of Fallot (ToF) with pulmonary atresia (ToF-PA) is a complex congenital heart defect at the extreme end of the spectrum of ToF, with no antegrade flow into the pulmonary arteries. Patients differ with regard to the sources of pulmonary blood flow. In the milder spectrum of disease, there are confluent branch pulmonary arteries fed by ductus arteriosus. In more severe cases, however, the ductus arteriosus is absent, and the sole source of pulmonary blood flow is via major aortopulmonary collateral arteries (MAPCAs). The variability in the origin, size, number, and clinical course of these MAPCAs adds to the complexity of these patients. Currently, the goal of management is to establish pulmonary blood flow from the right ventricle (RV) with RV pressures that are ideally less than half of the systemic pressure to allow for closure of the ventricular septal defect. In the long term, patients with ToF-PA are at higher risk for reinterventions to address pulmonary arterial or RV-pulmonary artery conduit stenosis, progressive aortic root dilation and aortic insufficiency, and late mortality than those with less severe forms of ToF.

Perioperative and Anesthetic Considerations in Tetralogy of Fallot With Pulmonary Atresia

2021 ◽  
Vol 25 (3) ◽  
pp. 218-228 ◽  
Author(s):  
Casey A. Quinlan ◽  
Gregory J. Latham ◽  
Denise Joffe ◽  
Faith J. Ross
Keyword(s):  
Blood Flow ◽  
Tetralogy Of Fallot ◽  
Pulmonary Blood Flow ◽  
Anesthetic Management ◽  
Ductus Arteriosus ◽  
Pulmonary Atresia ◽  
Systemic Circulation ◽  
Arterial System ◽  
Pulmonary Vasculature ◽  
Pulmonary Arterial

Tetralogy of Fallot with pulmonary atresia (ToF-PA) is a rare diagnosis that includes an extraordinarily heterogeneous group of complex anatomical findings with significant implications for physiology and prognosis. In addition to the classic findings of ToF, this particular diagnosis is characterized by complete failure of forward flow from the right ventricle to the pulmonary arterial system. As such, pulmonary blood flow is entirely dependent on shunting from the systemic circulation, most frequently via a patent ductus arteriosus, major aortopulmonary collaterals, or a combination of the two. The pathophysiology of ToF-PA is largely attributable to the abnormalities of the pulmonary vasculature. Ultimately, these patients require operative intervention to create a reliable, controlled source of pulmonary blood flow and ideally complete intracardiac repair. Even after operative correction, these patients remain at risk for pulmonary arterial stenoses and pulmonary hypertension. Although there have been significant advances in surgical and interventional management of ToF-PA leading to dramatic improvements in survival and long-term functional status, there is ongoing debate about the optimal management strategy given the risk of development of irreversible abnormalities of the pulmonary vasculature and the morbidity and mortality associated with sometimes multiple, complex operative interventions often occurring early in infancy. This review will discuss the findings in patients with ToF-PA with a focus on the perioperative and anesthetic management and will highlight challenges faced by the anesthesiologist in caring for these patients.

Abstract 14860: Echocardiographic Assessment of Shunt Fraction in Complex Cyanotic Heart Diseases Palliated With Aortopulmonary Shunts

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Joan K Lee ◽  
briana olson ◽  
Neal Jorgensen ◽  
Matthew D Files
Keyword(s):  
Blood Flow ◽  
Pulmonary Blood Flow ◽  
Heart Diseases ◽  
Heart Defects ◽  
Ductus Arteriosus ◽  
Ventricular Volume ◽  
Systemic Circulation ◽  
Repeated Measurements ◽  
Observer Agreement ◽  
Shunt Fraction

Introduction: Neonates with complex heart defects with inadequate pulmonary blood flow require aortopulmonary shunts (APS) either as surgical-placed modified Blalock-Taussig shunt or a catheter-based stent implantation into a patent ductus arteriosus. An ideal APS provides equal pulmonary blood flow (Qp) as the systemic blood flow (Qs), which is considered balanced circulation. Pulmonary over-circulation leads to complications from inadequate systemic circulation, such as organ dysfunction, shock, and death. Accurately determining Qp:Qs ratio in these patients relies on catheterization, which is invasive and may falsely lower the Qp due to anesthetic effects. To our knowledge, there has not been any studies on echocardiographic comparisons of balanced versus overcirculated APS. We aim to evaluate echocardiographic Doppler assessment of velocity-time integral (VTI) at the aortic arch isthmus distal to APS origin as a measure of shunt fraction in APS patients. We defined shunt fraction ratio (SFR) as retrograde to prograde flow by VTI. Methods: This is a retrospective pilot study of neonates with APS. We selected two cohorts of patients with appropriately balanced circulation (n=12) and those with excessive Qp (n=5) resulting in end-organ damage. We analyzed serial echocardiograms, with repeated measurements for inter-observer agreement. Results: Mean SFR is lower in balanced cohort compared to the overcirculated cohort (0.45 ± 0.07 vs. 0.55 ± 0.09, p=0.02). For both groups, SFR was positively associated with oxygen saturation (r= 0.57, p=0.01), as well as markers of ventricular volume load, such as the highest brain naturetic peptide during hospitalization (Pearson’s correlation r=0.83, p= 0.04) and as outpatient (r= 0.72, p =0.02). Inter-observer agreement was 0.74, suggesting that this is a reproducible technique. Conclusions: SFR by VTI is a simple echocardiographic technique to estimate the volume of APS flow and appears to have important implications for clinical outcomes. Prompt characterization of pulmonary overcirculation without invasive assessment could improve clinical management. Further prospective studies are needed to validate these findings.

Prolonged Prostaglandin E1 Infusion in an Infant With Cyanotic Congenital Heart Disease

PEDIATRICS ◽  
1978 ◽  
Vol 61 (4) ◽  
pp. 534-536
Author(s):  
Alan B. Lewis ◽  
Paul R. Lurie
Keyword(s):  
Congenital Heart Disease ◽  
Blood Flow ◽  
Heart Disease ◽  
Gestational Age ◽  
Small For Gestational Age ◽  
Pulmonary Blood Flow ◽  
Congenital Heart ◽  
Prostaglandin E1 ◽  
Ductus Arteriosus ◽  
Cyanotic Congenital Heart Disease

A small-for-gestational-age premature infant with severe tetralogy of Fallot was treated with prostaglandin E1 to dialate the ductus arteriosus and increase pulmonary blood flow. The infusion was continued for 29 days without complication at which time surgery was performed.

Ductus Arteriosus Dilatation by Prostaglandin E1 in Infants With Pulmonary Atresia

PEDIATRICS ◽  
1977 ◽  
Vol 59 (3) ◽  
pp. 325-329 ◽  
Author(s):  
Michael A. Heymann ◽  
Abraham M. Rudolph
Keyword(s):  
Central Nervous System ◽  
Pulmonary Blood Flow ◽  
Prostaglandin E1 ◽  
Ductus Arteriosus ◽  
Pulmonary Atresia ◽  
Postnatal Period ◽  
Descending Aorta ◽  
Arterial Blood ◽  
Surgical Palliation ◽  
The Central Nervous System

Infants with pulmonary atresia depend on patency of the ductus arteriosus for survival in the immediate postnatal period. Despite continuing hypoxemia after birth the ductus arteriosus usually constricts, thus reducing pulmonary blood flow. This often occurs while awaiting surgical palliation or correction, leading either to marked deterioration in the infant's condition, or death. In ten infants with pulmonary atresia, we infused prostaglandin E1 (PGE1) at a rate of 0.1µg/kg/min in six and 0.05µg/kg/min in four into the descending aorta at the orifice of the ductus arteriosus. The ductus arteriosus was effectively dilated: at the narrowest point the diameter, measured in eight infants, almost doubled. In all ten infants arterial blood PO2 increased, averaging 24.6 mm Hg before and 43.7 mm Hg after the infusion was started. Infusion of PGE1 directly into the aorta adjacent to the ductus arteriosus avoided the complications of pyrexia, muscular twitching, and excitability which may be related to the effects of prostaglandins on the central nervous system.

scholarly journals Bidirectional Ductal Shunting and Preductal to Postductal Oxygenation Gradient in Persistent Pulmonary Hypertension of the Newborn

Children ◽  
2020 ◽  
Vol 7 (9) ◽  
pp. 137
Author(s):  
Amy Lesneski ◽  
Morgan Hardie ◽  
William Ferrier ◽  
Satyan Lakshminrusimha ◽  
Payam Vali
Keyword(s):  
Blood Flow ◽  
Pulmonary Hypertension ◽  
Pulmonary Blood Flow ◽  
Ductus Arteriosus ◽  
Arterial Oxygen Tension ◽  
Persistent Pulmonary Hypertension ◽  
Arterial Oxygen ◽  
Meconium Aspiration ◽  
Arterial Blood Gas ◽  
Arterial Blood

Background: The aim was to evaluate the relationship between the direction of the patent ductus arteriosus (PDA) shunt and the pre- and postductal gradient for arterial blood gas (ABG) parameters in a lamb model of meconium aspiration syndrome (MAS) with persistent pulmonary hypertension of the newborn (PPHN). Methods: PPHN was induced by intermittent umbilical cord occlusion and the aspiration of meconium through the tracheal tube. After delivery, 13 lambs were ventilated and simultaneous 129 pairs of pre- and postductal ABG were drawn (right carotid and umbilical artery, respectively) while recording the PDA and the carotid and pulmonary blood flow. Results: Meconium aspiration resulted in hypoxemia. The bidirectional ductal shunt had a lower postductal partial arterial oxygen tension ([PaO2] with lower PaO2/FiO2 ratio—97 ± 36 vs. 130 ± 65 mmHg) and left pulmonary flow (81 ± 52 vs. 133 ± 82 mL/kg/min). However, 56% of the samples with a bidirectional shunt had a pre- and postductal saturation gradient of < 3%. Conclusions: The presence of a bidirectional ductal shunt is associated with hypoxemia and low pulmonary blood flow. The absence of a pre- and postductal saturation difference is frequently observed with bidirectional right-to-left shunting through the PDA, and does not exclude a diagnosis of PPHN in this model.

Sign in / Sign up

Export Citation Format

Share Document